physical field work (rivers) (paper 3)

Question 1

the location of our study area…

Answer 1

the bed burn beck which is a tributary of the river wear , it flows through hamsterly forrest which is quite a rural area of county durham in the north east of england

Question 2

what is the enquiry question

Answer 2

hypothesis - flood risk along the river wear increases downstream

Question 3

why were the sites we chose appropriate

Answer 3

they were accessible by mini bus

the sites were far apart enough to show changes in the channel and drainage basin characteristics

Question 4

what were the limitations of the chosen sites

Answer 4

we only investigated sites in the upper course on a tributary

Question 5

what is primary data

Answer 5

infomation that you collect yourself

Question 6

primary data we measured

Answer 6

velocity of the river

field sketch

width

gradient

depth

sediment survey

Question 7

field equipment we used …

Answer 7

ranging poles

tape measure

clinometer

ping pong balls

powers scale of roundness

Question 8

what is secondary data

Answer 8

infomation that someone else has previously collected and made available e.g on the internet

Question 9

what is Geographical Information System (GIS)

Answer 9

a way of displaying special data e.g a map with a flood risk layer on top

Question 10

secondary data sources i could use

Answer 10

land use map

geology map

drainage survey maps

Question 11

measurement errors

Answer 11

mistakes made by using the equipment incorrectly

Question 12

operator errors

Answer 12

caused by the person collecting the data e.g a difference in opinion/ personal bias

Question 13

what is accuracy

Answer 13

how precise the data is and how close to the true value the data is

Question 14

what is reliability

Answer 14

how correct the data is and how repeatable the results are

Question 15

weather conditions and dar of fieldwork

Answer 15

22nd of june 2023

weather was hot and dry , june was warmer than average for the uk

Question 16

width - method , explanation and evaluation

Answer 16

method - we stretched a tape measure from one bank to another holding it tawt above the surface of the water

explanation - width was measured to calculate the discharge, the wider the river the greater the discharge. where the discharge is highly , flooding is more likely

eval - sometimes the tape measure sagged in the middle , reducing the accuracy of the width data

Question 17

depth - method, explanation, evaluation

Answer 17

method - we used a metre ruler to measure the depth at 10 different points , we divided the width of the river by 10 to use a systematic sample

explanation - depth was measured to calculate discharge, the deeper the river the greater the discharge

eval - the meter ruler sank into the soft mud on the river bed , reducing the accuracy of the data

Question 18

velocity - method , explanation, evaluation

Answer 18

method - we used the float method to measure the speed of the river , we placed 2 ranging poles 2 metres apart and timed the ball

explanation - velocity was measured to calculate the discharge , the faster the river the greater the discharge

eval - we did 3 velocity readings at each site and calculated an average , this improved the accuracy of the data
somethings the balls got stuck on the banks , a flow meter would have been more accurate

Question 19

how to calculate discharge

Answer 19

velocity X (width x depth)

Question 20

gradient - method, explanation, evaluation

Answer 20

method - measured a distance of 2 metres using a tape measure and marked it using 2 ranging poles, we used a clinometer to measure the gradient in degrees

explanation - the steeper the gradient of the drainage basin the less infiltration there is and the quicker rain water gets into the river, increasing flood risk

eval - we had never used a clinometer before so may have used it incorrectly, sometimes the ranging poles were tilted instead of vertical
these factors reduce the accuracy of the data

Question 21

sediment survey - method, explanation, evaluation

Answer 21

method - we selected one rock next to each depth reading and measured it’s longest edge, we then used powers scale of roundness to categorise the rock into class 1-6

explanation - the smaller and rounded the sediment the more erosion is taking place , where there is a lot of erosion the river has more energy and therefore is more likely to flood

eval - there were operator errors because people were more likely to pick up larger rocks and there was some disagreement about the powers class, this reduces accuracy

Question 22

drainage basin characteristics (field sketch) - method , explanation and evaluation

Answer 22

method - we observed the river at each site and drew its main features, we added annotations to describe the environment

explanation - land use shows the value of land , the higher value the land the greater the risk if it’s flooded . The vegetation cover shows how much interception will take place, more vegetation reduces the risk of flooding

eval - a sketch allows you to focus on specific features that are relevant to your study , they also provide a visual reminder when analysing results